Place the pan in the oven 5 minutes before using. Heating the pan before the patty touches it will sear the patty quickly, locking in the juices. Place the patty on the baking pan, using the cooking tongs. Bake the patty for 5 minutes. After 5 minutes, juices will start to appear on the surface of the patty. This is a good indication that the inside of the patty is being cooked. Pull the pan out of the oven with oven mitts. Flip the patty with cooking tongs. Stuffed Portobello Mushroom Recipes. Add 14 cup each of diced green pepper and chopped onion to the surface of the patty. Return the pan to the oven. Bake for an additional 5 to 1. Stick a meat thermometer into the center of the patty. Make sure it reads a minimum internal temperature of 1. F. Nonstick cooking spray. Baking pan. 14 lb. Cooking tongs. Oven mitts. Meat thermometer. The most popular additions to a burger, after salt and pepper, are chopped onion and garlic powder. If you refrigerate the patty, keep at 4. F or below and use within 2 days. Never leave ground beef out at room temperature for more than 2 hours.